Safety device for gas burners



www@ 1 R. 5. TAYLOR ENCE FOR GAS BURNER SAFETY D Filed 29, 1930 'Patented Jan. l, 1935 UNITED STATESv SAFETY DEVICE FOR GS BURNERS Robert S. Taylor, New York, N. Y., assi-gnor to Electrolux Servel Corporation, New York, N. Y., a corporation of Delaware Application August 29, 1930, Serial No. 478,619 sclaims. (o1. s-117.1)

This invention relates to burners and more particularly toa safety device for a gas burner automatically operable to cut oi the flow of gas to the burner when the flame is extin- 5 guished, but which will not interfere with a free supply of gas and vcause `,faulty combustion during the normal operation of the burner.

It is an object'of thev invention to provide a thermostatic safety valve for a burner having an adjustable temperature responsive element which can be easily and cheaply replaced in the field, and is less expensive to manufacture than other devices of this character. It is a further object to provide such a valve which can be opened without the application of heat.

In the drawing,

Fig. 1 is a central verticalsection illustrating one applicationy ofthe invention;

Fig. 2 is a top plan view;

Fig. 3 is an enlarged fragmentary section with the valve in a different position from that of Fig. 1; and

Fig. 4 a section on the line 4-4 of Fig. 3.

In the drawing, reference character 10 indicates a burner tube preferably having a constricted lower portion communicatingV with a mixing chamber 11 provided with airports 12.

An adjustable sleeve 13 is rotatably mounted about the mixing chamber and a reticulated sleeve or screen 14 is provided for filtering the air passing to the burner. A removable orifice 15 is provided for admitting gas into the mixing chamber and the flow of gas through this orice is controlled by a needle valve 16. A plug 17 is provided for closing the passage in which the needle valve is mounted to avoid unauthorized tampering with the valve and to prevent possibility of gas leakage. The gas inlet pipe 18 has one end communicating with the adjustable orifice and extends upwardly in substantially parallel relation to the burner tube 10 and at the upper end forms a valve chamber comprising a transverse passage threaded at 19 for connection with the source of supply. In the valve chamber there is a cut-off valve comprising a valve seat 20 engaged by a valve head 21 mounted upon a valve stem 22, which valve controls the supply of gas'through the inlet pipe 18 to the burner.

Between the upper end of the inlet pipe and the burner tube is mounted a` casing which consists of a frusta-conical or cupped member 23 and a flexible spring metal disc 24 which forms the bottom of the same. The small end of the cupped member is threaded upon .the

inlet pipe to form a gas tight joint and the large end of the cupped member is crimped over the outer edge of the-,resilient diaphragm 24, a thin gasket 25'being preferably providedto pre' vent. leakage. The valve stem 22 extends 5 Athrough the central portion of this -spring mem- .ber v24, which latter forms a resilient wall portion of the valve chamber, and is secured thereto by means of a clamping ring or nut 26. A gasket 26a can be used here also 'if desired. 10 Flexing the diaphragm 24 will seat and unseat the valve 21 and the diaphragm seals the valve chamber against escape of gas. In devices of this character previouslyconstructed, the member 24 has been of bi-metallic construction adapted to open vand `close the valve responsive to change in temperature. In the present invention, the disc 24 is preferably constructed of phosphor bronze or other spring metal which will snap back and forthv like the bottom of an oil can when force is applied to it. In order to supply Athe force for snapping the disc in a mannerv to open the valve, a resilient bi-metallic plate 27 is detachably and adjustably secured at one end to the inlet pipe by means of vscrews 28, said plate being provided with slots through which the screws 28 extend. This bi-metallic plate has its free end disposed in front of the valve operating disc 24 so that when such free end of the plate moves as a result of being heated, it will b ear against the disc 24 and open the valve. -In order to conduct heat from the burner fiame to this bi-metallic plate, a' thert mal conductive strip 29 is clamped around the intermediate portion of the plate, and such strip preferably has an arcuate extension or upstanding tab 30 disposed in close proximity to the end of the burner tube so that it will be directly heated by the gas flame.

On account of the adjustable mounting of this bi-metallic element a ne adjustment ci?A the valve operation may be obtained. As soon as the flame is extinguished or becomes so small that the conductor strip and bi-metallic element cools, the pressure of the. bi-metallic element upon the spring disc which operates the valve will be relieved and the .valve will be caused to engage its seat by the snap-action of the spring disc 24, the bi-metallic element yielding to permit the disc 24 to moveY outwardly to seat the valve. y

When it is desired to-'light the burner, the bimetallic elemnt may be pressed to unseat the valve to permit'the gas to flow and after holding it'in `this position for a time, heat will be transferred tothe bi-metallic element and cause the same to engage and hold the valve open.

It will be obvious to those skilled in the art that various changes may be made in the construction and arrangement without departing from the spirit of the invention and therefore Athe invention is not limited to what is shown mally maintain the valve closed and to suddenly `open the valve when pressure is exerted on the `"spring metal disc, and a resilient bi-metallic element having a portion lying in proximity to said disc and operable when heated to exert a continuous pressure upon said disc and operable when cooled to release the pressure from said.

disc and permit the valve to snap closed.

2. In combination with a gas burner, a safety device comprising a gas supply conduit for the burner, a valve in said conduit for controlling the supply of fuel to the burner, a snap-action spring metal disc operative to maintain the valve closed and to suddenly open the valve when pressure is exerted on the spring metal disc, and means for actuating the 'disc including a resilient bi-metallic element having a portion in proximity to saiddisc' and subject to heat produced by the burner and operable' when heated to automatically cause the disc to snap the valve open and when cooled to automatically cause the disc to snap the valve closed.

3. A safety device comprising a valve, a snapaction spring metal disc operative to maintain the valve closed and to suddenly open the valve when pressure is exerted on the spring metal disc, and means for actuating the disc including a resilient bi-metallic element having a portion in proximity to said disc and operable when heated to automatically cause the disc to snap the valve open and whenV cooled to automatically cause the disc to snap the valve closed.

`ROBERT s. TAYLDR. 

